“He hasn’t got a plan yet,” Jenna Coleman‘s Clara Oswald tells Maisie‘s mysterious character in the new trailer of the Doctor (Peter Capaldi). “But he will have…and it will be spectacular.”

Showrunner Steven Moffatrecently told press about Maisie‘s character that “she is a brand new character. She is not someone from the Doctor’s past…It’s a great part and she’s terrific in it. It will develop in unexpected ways. Once you see what she’s up to in the show, you’ll appreciate what a clever [idea that was]. It’s a significant role. We’re not throwing her away.”

Doctor Who returns on Saturday, September 19th @ 9PM ET/PT on BBC America.